diff --git a/tree/ntuple/inc/ROOT/RMiniFile.hxx b/tree/ntuple/inc/ROOT/RMiniFile.hxx
index f7614695b0067..8c1205416d09b 100644
--- a/tree/ntuple/inc/ROOT/RMiniFile.hxx
+++ b/tree/ntuple/inc/ROOT/RMiniFile.hxx
@@ -68,6 +68,10 @@ private:
    /// what happens in `RNTupleFileWriter::WriteBlob()`.
    std::uint64_t fMaxKeySize = 0;
 
+   /// Information about the streamer info record cache on file open from the TFile header. Used in LoadStreamerInfo.
+   std::uint64_t fSeekKeyInfo = 0;
+   std::uint64_t fNbytesKeyAndInfo = 0;
+
    /// Used when the file container turns out to be a bare file
    RResult<RNTuple> GetNTupleBare(std::string_view ntupleName);
    /// Used when the file turns out to be a TFile container. The ntuplePath variable is either the ntuple name
@@ -96,7 +100,7 @@ public:
    void ReadBuffer(void *buffer, size_t nbytes, std::uint64_t offset);
    /// Like ReadBuffer but returns a RResult instead of throwing.
    ROOT::RResult<void> TryReadBuffer(void *buffer, size_t nbytes, std::uint64_t offset);
-   /// Attempts to load the streamer info from the file.
+   /// Load the streamer info from the file into the global list of streamer infos
    void LoadStreamerInfo();
 
    std::uint64_t GetMaxKeySize() const { return fMaxKeySize; }
diff --git a/tree/ntuple/inc/ROOT/RPageStorage.hxx b/tree/ntuple/inc/ROOT/RPageStorage.hxx
index b670e5989a447..dfcf2d11d411c 100644
--- a/tree/ntuple/inc/ROOT/RPageStorage.hxx
+++ b/tree/ntuple/inc/ROOT/RPageStorage.hxx
@@ -906,10 +906,6 @@ public:
    /// connecting streamer fields so that emulated classes can be read.
    void RegisterStreamerInfos();
 
-   /// Forces the loading of ROOT StreamerInfo from the underlying file. This currently only has an effect for
-   /// TFile-backed sources.
-   virtual void LoadStreamerInfo() = 0;
-
    /// Creates a new PageSource using the same underlying file as this but referring to a different RNTuple,
    /// described by `anchorLink`.
    virtual std::unique_ptr<RPageSource> OpenWithDifferentAnchor(const ROOT::Internal::RNTupleLink &anchorLink,
diff --git a/tree/ntuple/inc/ROOT/RPageStorageDaos.hxx b/tree/ntuple/inc/ROOT/RPageStorageDaos.hxx
index d2b017516d2ab..b5ff59bddd0e6 100644
--- a/tree/ntuple/inc/ROOT/RPageStorageDaos.hxx
+++ b/tree/ntuple/inc/ROOT/RPageStorageDaos.hxx
@@ -176,8 +176,6 @@ public:
    /// Return the object class used for user data OIDs in this ntuple.
    std::string GetObjectClass() const;
 
-   void LoadStreamerInfo() final;
-
    std::unique_ptr<RPageSource> OpenWithDifferentAnchor(const ROOT::Internal::RNTupleLink &anchorLink,
                                                         const ROOT::RNTupleReadOptions &options = {}) final;
 }; // class RPageSourceDaos
diff --git a/tree/ntuple/inc/ROOT/RPageStorageFile.hxx b/tree/ntuple/inc/ROOT/RPageStorageFile.hxx
index c1881042c4ee3..d94feff68f1e7 100644
--- a/tree/ntuple/inc/ROOT/RPageStorageFile.hxx
+++ b/tree/ntuple/inc/ROOT/RPageStorageFile.hxx
@@ -189,8 +189,6 @@ public:
 
    std::vector<std::unique_ptr<ROOT::Internal::RCluster>>
    LoadClusters(std::span<ROOT::Internal::RCluster::RKey> clusterKeys) final;
-
-   void LoadStreamerInfo() final;
 }; // class RPageSourceFile
 
 } // namespace Internal
diff --git a/tree/ntuple/src/RMiniFile.cxx b/tree/ntuple/src/RMiniFile.cxx
index 79048d0a9f016..bd4e95fd7bfd2 100644
--- a/tree/ntuple/src/RMiniFile.cxx
+++ b/tree/ntuple/src/RMiniFile.cxx
@@ -723,16 +723,15 @@ std::uint64_t ROOT::Internal::RMiniFileReader::SearchInDirectory(std::uint64_t &
 
 void ROOT::Internal::RMiniFileReader::LoadStreamerInfo()
 {
-   RTFHeader fileHeader;
-   ReadBuffer(&fileHeader, sizeof(fileHeader), 0);
-
-   const std::uint64_t seekKeyInfo = fileHeader.GetSeekInfo();
+   if (fIsBare == 0)
+      return;
 
    RTFKey key;
-   ReadBuffer(&key, sizeof(key), seekKeyInfo);
+   ReadBuffer(&key, sizeof(key), fSeekKeyInfo);
 
-   const std::uint64_t nbytesInfo = fileHeader.GetNbytesInfo() - key.fKeyLen;
-   const std::uint64_t seekInfo = seekKeyInfo + key.fKeyLen;
+   R__ASSERT(fNbytesKeyAndInfo >= key.fKeyLen);
+   const std::uint64_t nbytesInfo = fNbytesKeyAndInfo - key.fKeyLen;
+   const std::uint64_t seekInfo = fSeekKeyInfo + key.fKeyLen;
    const std::uint32_t uncompLenInfo = key.fObjLen;
    auto streamerInfo = MakeUninitArray<char>(uncompLenInfo);
    if (nbytesInfo == uncompLenInfo) {
@@ -770,6 +769,9 @@ ROOT::RResult<ROOT::RNTuple> ROOT::Internal::RMiniFileReader::GetNTupleProper(st
    RTFHeader fileHeader;
    ReadBuffer(&fileHeader, sizeof(fileHeader), 0);
 
+   fSeekKeyInfo = fileHeader.GetSeekInfo();
+   fNbytesKeyAndInfo = fileHeader.GetNbytesInfo();
+
    RTFKey key;
    RTFString name;
    ReadBuffer(&key, sizeof(key), fileHeader.fBEGIN);
@@ -817,6 +819,7 @@ ROOT::RResult<ROOT::RNTuple> ROOT::Internal::RMiniFileReader::GetNTupleProper(st
 
    const auto objNbytes = key.GetSize() - key.fKeyLen;
    auto res = GetNTupleProperAtOffset(offset, objNbytes, key.fObjLen);
+
    return res;
 }
 
diff --git a/tree/ntuple/src/RNTupleMerger.cxx b/tree/ntuple/src/RNTupleMerger.cxx
index 3b54445c39287..7d88c4070fc3c 100644
--- a/tree/ntuple/src/RNTupleMerger.cxx
+++ b/tree/ntuple/src/RNTupleMerger.cxx
@@ -1393,10 +1393,6 @@ ROOT::RResult<void> RNTupleMerger::Merge(std::span<RPageSource *> sources, const
 
    // Merge main loop
    for (RPageSource *source : sources) {
-      // We need to make sure the streamer info from the source files is loaded otherwise we may not be able
-      // to build the streamer info of user-defined types unless we have their dictionaries available.
-      source->LoadStreamerInfo();
-
       source->Attach(RNTupleSerializer::EDescriptorDeserializeMode::kForWriting);
       auto srcDescriptor = source->GetSharedDescriptorGuard();
       mergeData.fSrcDescriptor = &srcDescriptor.GetRef();
diff --git a/tree/ntuple/src/RPageStorageDaos.cxx b/tree/ntuple/src/RPageStorageDaos.cxx
index 7e5651f8d6761..0e3bffc8d0c6c 100644
--- a/tree/ntuple/src/RPageStorageDaos.cxx
+++ b/tree/ntuple/src/RPageStorageDaos.cxx
@@ -596,11 +596,6 @@ ROOT::Experimental::Internal::RPageSourceDaos::LoadClusters(std::span<RCluster::
    return clusters;
 }
 
-void ROOT::Experimental::Internal::RPageSourceDaos::LoadStreamerInfo()
-{
-   R__LOG_WARNING(ROOT::Internal::NTupleLog()) << "DAOS-backed sources have no associated StreamerInfo to load.";
-}
-
 std::unique_ptr<ROOT::Internal::RPageSource>
 ROOT::Experimental::Internal::RPageSourceDaos::OpenWithDifferentAnchor(const ROOT::Internal::RNTupleLink &,
                                                                        const ROOT::RNTupleReadOptions &)
diff --git a/tree/ntuple/src/RPageStorageFile.cxx b/tree/ntuple/src/RPageStorageFile.cxx
index 3e7ffd15eba40..effcdd4bd9a06 100644
--- a/tree/ntuple/src/RPageStorageFile.cxx
+++ b/tree/ntuple/src/RPageStorageFile.cxx
@@ -425,6 +425,10 @@ void ROOT::Internal::RPageSourceFile::LoadStructureImpl()
    // Otherwise, the page source was created by OpenFromAnchor()
    if (!fAnchor) {
       fAnchor = fReader.GetNTuple(fNTupleName).Unwrap();
+      // We couple finding the RNTuple anchor to loading the streamer infos.
+      // If we already have the anchor, we must have opened the file before (either through TFile or by the source of
+      // OpenWithDifferentAnchor(), in which case we already loaded the streamer info) .
+      fReader.LoadStreamerInfo();
    }
    fReader.SetMaxKeySize(fAnchor->GetMaxKeySize());
 
@@ -711,8 +715,3 @@ ROOT::Internal::RPageSourceFile::LoadClusters(std::span<RCluster::RKey> clusterK
 
    return clusters;
 }
-
-void ROOT::Internal::RPageSourceFile::LoadStreamerInfo()
-{
-   fReader.LoadStreamerInfo();
-}
diff --git a/tree/ntuple/test/ntuple_cluster.cxx b/tree/ntuple/test/ntuple_cluster.cxx
index 32808d8a0830e..6121a09d61e1e 100644
--- a/tree/ntuple/test/ntuple_cluster.cxx
+++ b/tree/ntuple/test/ntuple_cluster.cxx
@@ -43,7 +43,6 @@ class RPageSourceMock : public RPageSource {
    std::unique_ptr<RPageSource> CloneImpl() const final { return nullptr; }
    void LoadPageListImpl(const ROOT::RNTupleLocator &, unsigned char *) final {}
    void LoadSealedPageImpl(const ROOT::RNTupleLocator &, RSealedPage &) final {}
-   void LoadStreamerInfo() final {}
    std::unique_ptr<ROOT::Internal::RPageSource>
    OpenWithDifferentAnchor(const ROOT::Internal::RNTupleLink &, const ROOT::RNTupleReadOptions &) final
    {
diff --git a/tree/ntuple/test/ntuple_emulated.cxx b/tree/ntuple/test/ntuple_emulated.cxx
index 013a8f1fd30bf..d61f7a5d6c84f 100644
--- a/tree/ntuple/test/ntuple_emulated.cxx
+++ b/tree/ntuple/test/ntuple_emulated.cxx
@@ -9,6 +9,8 @@ TEST(RNTupleEmulated, EmulatedFields_Simple)
 
    FileRaii fileGuard("test_ntuple_emulated_fields.root");
 
+   EXPECT_NO_STREAMER_OR_DICTIONARY();
+
    ExecInFork([&] {
       // The child process writes the file and exits, but the file must be preserved to be read by the parent.
       fileGuard.PreserveFile();
@@ -32,12 +34,6 @@ TEST(RNTupleEmulated, EmulatedFields_Simple)
       auto model = RNTupleModel::Create();
       model->AddField(RFieldBase::Create("f", "Outer_Simple").Unwrap());
 
-      // TStreamerInfo::Build will report a warning for interpreted classes (but only for members).
-      // See also https://github.com/root-project/root/issues/9371
-      ROOT::TestSupport::CheckDiagsRAII diagRAII;
-      diagRAII.optionalDiag(kWarning, "TStreamerInfo::Build", "has no streamer or dictionary",
-                            /*matchFullMessage=*/false);
-
       auto writer = RNTupleWriter::Recreate(std::move(model), "ntpl", fileGuard.GetPath());
       writer->Fill();
 
@@ -93,9 +89,6 @@ TEST(RNTupleEmulated, EmulatedFields_Simple)
    RNTupleDescriptor::RCreateModelOptions cmOpts;
    cmOpts.SetEmulateUnknownTypes(true);
 
-   ROOT::TestSupport::CheckDiagsRAII diagRAII;
-   diagRAII.optionalDiag(kWarning, "TClass::Init", "no dictionary for class",
-                         /*matchFullMessage=*/false);
    std::unique_ptr<TFile> file(TFile::Open(fileGuard.GetPath().c_str()));
    std::unique_ptr<ROOT::RNTuple> ntpl(file->Get<ROOT::RNTuple>("ntpl"));
    reader = RNTupleReader::Open(cmOpts, *ntpl);
@@ -121,6 +114,8 @@ TEST(RNTupleEmulated, EmulatedFields_Vecs)
 
    FileRaii fileGuard("test_ntuple_emulated_fields_vecs.root");
 
+   EXPECT_NO_STREAMER_OR_DICTIONARY();
+
    ExecInFork([&] {
       // The child process writes the file and exits, but the file must be preserved to be read by the parent.
       fileGuard.PreserveFile();
@@ -144,12 +139,6 @@ TEST(RNTupleEmulated, EmulatedFields_Vecs)
       auto model = RNTupleModel::Create();
       model->AddField(RFieldBase::Create("outers", "std::vector<Outer_Vecs>").Unwrap());
 
-      // TStreamerInfo::Build will report a warning for interpreted classes (but only for members).
-      // See also https://github.com/root-project/root/issues/9371
-      ROOT::TestSupport::CheckDiagsRAII diagRAII;
-      diagRAII.optionalDiag(kWarning, "TStreamerInfo::Build", "has no streamer or dictionary",
-                            /*matchFullMessage=*/false);
-
       auto writer = RNTupleWriter::Recreate(std::move(model), "ntpl", fileGuard.GetPath());
       writer->Fill();
 
@@ -222,6 +211,8 @@ TEST(RNTupleEmulated, EmulatedFields_VecsTemplatedWrapper)
 {
    FileRaii fileGuard("test_ntuple_emulated_fields_vecs_templated_wrapper.root");
 
+   EXPECT_NO_STREAMER_OR_DICTIONARY();
+
    ExecInFork([&] {
       // The child process writes the file and exits, but the file must be preserved to be read by the parent.
       fileGuard.PreserveFile();
@@ -298,6 +289,8 @@ TEST(RNTupleEmulated, EmulatedFields_EmptyStruct)
 
    FileRaii fileGuard("test_ntuple_emulated_emptystruct.root");
 
+   EXPECT_NO_STREAMER_OR_DICTIONARY();
+
    ExecInFork([&] {
       // The child process writes the file and exits, but the file must be preserved to be read by the parent.
       fileGuard.PreserveFile();
@@ -316,12 +309,6 @@ TEST(RNTupleEmulated, EmulatedFields_EmptyStruct)
       auto model = RNTupleModel::Create();
       model->AddField(RFieldBase::Create("f", "Outer_EmptyStruct").Unwrap());
 
-      // TStreamerInfo::Build will report a warning for interpreted classes (but only for members).
-      // See also https://github.com/root-project/root/issues/9371
-      ROOT::TestSupport::CheckDiagsRAII diagRAII;
-      diagRAII.optionalDiag(kWarning, "TStreamerInfo::Build", "has no streamer or dictionary",
-                            /*matchFullMessage=*/false);
-
       auto writer = RNTupleWriter::Recreate(std::move(model), "ntpl", fileGuard.GetPath());
       writer->Fill();
    });
@@ -373,6 +360,8 @@ TEST(RNTupleEmulated, EmulatedFields_EmptyVec)
 
    FileRaii fileGuard("test_ntuple_emulated_emptyvec.root");
 
+   EXPECT_NO_STREAMER_OR_DICTIONARY();
+
    ExecInFork([&] {
       // The child process writes the file and exits, but the file must be preserved to be read by the parent.
       fileGuard.PreserveFile();
@@ -396,11 +385,6 @@ TEST(RNTupleEmulated, EmulatedFields_EmptyVec)
       ProcessLine("ptrInners->push_back(Inner_EmptyVec{});");
       ProcessLine("ptrInners->push_back(Inner_EmptyVec{});");
 
-      // TStreamerInfo::Build will report a warning for interpreted classes (but only for members).
-      // See also https://github.com/root-project/root/issues/9371
-      ROOT::TestSupport::CheckDiagsRAII diagRAII;
-      diagRAII.optionalDiag(kWarning, "TStreamerInfo::Build", "has no streamer or dictionary",
-                            /*matchFullMessage=*/false);
       writer.reset();
    });
 
@@ -453,6 +437,8 @@ TEST(RNTupleEmulated, EmulatedFields_Write)
 
    FileRaii fileGuard("test_ntuple_emulated_write.root");
 
+   EXPECT_NO_STREAMER_OR_DICTIONARY();
+
    ExecInFork([&] {
       fileGuard.PreserveFile();
 
@@ -476,11 +462,6 @@ TEST(RNTupleEmulated, EmulatedFields_Write)
       auto writer = RNTupleWriter::Recreate(std::move(model), "ntpl", fileGuard.GetPath());
       writer->Fill();
 
-      // TStreamerInfo::Build will report a warning for interpreted classes (but only for members).
-      // See also https://github.com/root-project/root/issues/9371
-      ROOT::TestSupport::CheckDiagsRAII diagRAII;
-      diagRAII.optionalDiag(kWarning, "TStreamerInfo::Build", "has no streamer or dictionary",
-                            /*matchFullMessage=*/false);
       writer.reset();
    });
 
@@ -504,6 +485,8 @@ TEST(RNTupleEmulated, CollectionProxy)
 {
    FileRaii fileGuard("test_ntuple_emulated_collproxy.root");
 
+   EXPECT_NO_STREAMER_OR_DICTIONARY();
+
    // Declare a custom type in a separate process, then write it through a custom collection proxy.
    // In the main process we load the generated RNTuple without having its dictionary available and we verify
    // we can read it (only) via field emulation (as an untyped VectorField).
@@ -648,11 +631,6 @@ TEST(RNTupleEmulated, CollectionProxy)
       ProcessLine("pProxyC->v.clear();");
       writer->Fill();
 
-      // TStreamerInfo::Build will report a warning for interpreted classes (but only for members).
-      // See also https://github.com/root-project/root/issues/9371
-      ROOT::TestSupport::CheckDiagsRAII diagRAII;
-      diagRAII.optionalDiag(kWarning, "TStreamerInfo::Build", "has no streamer or dictionary",
-                            /*matchFullMessage=*/false);
       writer.reset();
    });
 
@@ -692,6 +670,8 @@ TEST(RNTupleEmulated, MergeEmulated)
    FileRaii fileGuard2("test_ntuple_merge_emulated2.root");
    FileRaii fileGuardOut("test_ntuple_merge_emulated_out.root");
 
+   EXPECT_NO_STREAMER_OR_DICTIONARY();
+
    ExecInFork([&] {
       fileGuard1.PreserveFile();
       fileGuard2.PreserveFile();
@@ -726,11 +706,6 @@ TEST(RNTupleEmulated, MergeEmulated)
       ProcessLine("ptr2->fInt2 = 66;");
       writer2->Fill();
 
-      // TStreamerInfo::Build will report a warning for interpreted classes (but only for members).
-      // See also https://github.com/root-project/root/issues/9371
-      ROOT::TestSupport::CheckDiagsRAII diagRAII;
-      diagRAII.optionalDiag(kWarning, "TStreamerInfo::Build", "has no streamer or dictionary",
-                            /*matchFullMessage=*/false);
       writer.reset();
       writer2.reset();
    });
@@ -745,9 +720,6 @@ TEST(RNTupleEmulated, MergeEmulated)
    }
 
    {
-      ROOT::TestSupport::CheckDiagsRAII diagRAII;
-      diagRAII.requiredDiag(kWarning, "TClass::Init", "no dictionary", /*matchFullMessage=*/false);
-
       auto destination = std::make_unique<RPageSinkFile>("ntuple", fileGuardOut.GetPath(), RNTupleWriteOptions());
       RNTupleMerger merger{std::move(destination)};
       auto res = merger.Merge(sourcePtrs);
diff --git a/tree/ntuple/test/ntuple_endian.cxx b/tree/ntuple/test/ntuple_endian.cxx
index a1b22baf4adfe..9255a5d5c46ff 100644
--- a/tree/ntuple/test/ntuple_endian.cxx
+++ b/tree/ntuple/test/ntuple_endian.cxx
@@ -93,7 +93,6 @@ class RPageSourceMock : public RPageSource {
    std::unique_ptr<RPageSource> CloneImpl() const final { return nullptr; }
    void LoadPageListImpl(const ROOT::RNTupleLocator &, unsigned char *) final {}
    void LoadSealedPageImpl(const ROOT::RNTupleLocator &, RSealedPage &) final {}
-   void LoadStreamerInfo() final {}
 
    std::unique_ptr<ROOT::Internal::RPageSource>
    OpenWithDifferentAnchor(const ROOT::Internal::RNTupleLink &, const ROOT::RNTupleReadOptions &) final
diff --git a/tree/ntuple/test/ntuple_evolution_shape.cxx b/tree/ntuple/test/ntuple_evolution_shape.cxx
index e06a6c46acc42..e0befde54ec88 100644
--- a/tree/ntuple/test/ntuple_evolution_shape.cxx
+++ b/tree/ntuple/test/ntuple_evolution_shape.cxx
@@ -114,6 +114,8 @@ TEST(RNTupleEvolution, AddedMemberObject)
 {
    FileRaii fileGuard("test_ntuple_evolution_added_member_object.root");
 
+   EXPECT_NO_STREAMER_OR_DICTIONARY();
+
    ExecInFork([&] {
       // The child process writes the file and exits, but the file must be preserved to be read by the parent.
       fileGuard.PreserveFile();
@@ -131,12 +133,6 @@ struct AddedMemberObject {
       auto model = RNTupleModel::Create();
       model->AddField(RFieldBase::Create("f", "AddedMemberObject").Unwrap());
 
-      // TStreamerInfo::Build will report a warning for interpreted classes (but only for members).
-      // See also https://github.com/root-project/root/issues/9371
-      ROOT::TestSupport::CheckDiagsRAII diagRAII;
-      diagRAII.optionalDiag(kWarning, "TStreamerInfo::Build", "has no streamer or dictionary",
-                            /*matchFullMessage=*/false);
-
       auto writer = RNTupleWriter::Recreate(std::move(model), "ntpl", fileGuard.GetPath());
       writer->Fill();
 
@@ -357,6 +353,8 @@ TEST(RNTupleEvolution, RenamedMemberClass)
    // RNTuple currently does not support automatic schema evolution when a class is renamed.
    FileRaii fileGuard("test_ntuple_evolution_renamed_member_class.root");
 
+   EXPECT_NO_STREAMER_OR_DICTIONARY();
+
    ExecInFork([&] {
       // The child process writes the file and exits, but the file must be preserved to be read by the parent.
       fileGuard.PreserveFile();
@@ -373,12 +371,6 @@ struct RenamedMemberClass {
       auto model = RNTupleModel::Create();
       model->AddField(RFieldBase::Create("f", "RenamedMemberClass").Unwrap());
 
-      // TStreamerInfo::Build will report a warning for interpreted classes (but only for members).
-      // See also https://github.com/root-project/root/issues/9371
-      ROOT::TestSupport::CheckDiagsRAII diagRAII;
-      diagRAII.optionalDiag(kWarning, "TStreamerInfo::Build", "has no streamer or dictionary",
-                            /*matchFullMessage=*/false);
-
       auto writer = RNTupleWriter::Recreate(std::move(model), "ntpl", fileGuard.GetPath());
       writer->Fill();
    });
@@ -448,6 +440,8 @@ TEST(RNTupleEvolution, AddedBaseClass)
 {
    FileRaii fileGuard("test_ntuple_evolution_added_base_class.root");
 
+   EXPECT_NO_STREAMER_OR_DICTIONARY();
+
    ExecInFork([&] {
       // The child process writes the file and exits, but the file must be preserved to be read by the parent.
       fileGuard.PreserveFile();
@@ -464,12 +458,6 @@ struct AddedBaseDerived : public AddedBaseIntermediate {
       auto model = RNTupleModel::Create();
       model->AddField(RFieldBase::Create("f", "AddedBaseDerived").Unwrap());
 
-      // TStreamerInfo::Build will report a warning for interpreted classes (but only for base classes).
-      // See also https://github.com/root-project/root/issues/9371
-      ROOT::TestSupport::CheckDiagsRAII diagRAII;
-      diagRAII.optionalDiag(kWarning, "TStreamerInfo::Build", "has no streamer or dictionary",
-                            /*matchFullMessage=*/false);
-
       auto writer = RNTupleWriter::Recreate(std::move(model), "ntpl", fileGuard.GetPath());
       writer->Fill();
 
@@ -513,6 +501,8 @@ TEST(RNTupleEvolution, AddedSecondBaseClass)
 {
    FileRaii fileGuard("test_ntuple_evolution_added_second_base_class.root");
 
+   EXPECT_NO_STREAMER_OR_DICTIONARY();
+
    ExecInFork([&] {
       // The child process writes the file and exits, but the file must be preserved to be read by the parent.
       fileGuard.PreserveFile();
@@ -529,12 +519,6 @@ struct AddedSecondBaseDerived : public AddedSecondBaseFirst {
       auto model = RNTupleModel::Create();
       model->AddField(RFieldBase::Create("f", "AddedSecondBaseDerived").Unwrap());
 
-      // TStreamerInfo::Build will report a warning for interpreted classes (but only for base classes).
-      // See also https://github.com/root-project/root/issues/9371
-      ROOT::TestSupport::CheckDiagsRAII diagRAII;
-      diagRAII.optionalDiag(kWarning, "TStreamerInfo::Build", "has no streamer or dictionary",
-                            /*matchFullMessage=*/false);
-
       auto writer = RNTupleWriter::Recreate(std::move(model), "ntpl", fileGuard.GetPath());
       writer->Fill();
 
@@ -572,6 +556,8 @@ TEST(RNTupleEvolution, PrependSecondBaseClass)
    // automatically evolve this case, even if the member fields and on-disk columns are compatible.
    FileRaii fileGuard("test_ntuple_evolution_prepend_second_base_class.root");
 
+   EXPECT_NO_STREAMER_OR_DICTIONARY();
+
    ExecInFork([&] {
       // The child process writes the file and exits, but the file must be preserved to be read by the parent.
       fileGuard.PreserveFile();
@@ -588,12 +574,6 @@ struct PrependSecondBaseDerived : public PrependSecondBaseFirst {
       auto model = RNTupleModel::Create();
       model->AddField(RFieldBase::Create("f", "PrependSecondBaseDerived").Unwrap());
 
-      // TStreamerInfo::Build will report a warning for interpreted classes (but only for base classes).
-      // See also https://github.com/root-project/root/issues/9371
-      ROOT::TestSupport::CheckDiagsRAII diagRAII;
-      diagRAII.optionalDiag(kWarning, "TStreamerInfo::Build", "has no streamer or dictionary",
-                            /*matchFullMessage=*/false);
-
       auto writer = RNTupleWriter::Recreate(std::move(model), "ntpl", fileGuard.GetPath());
       writer->Fill();
    });
@@ -623,6 +603,8 @@ TEST(RNTupleEvolution, AddedIntermediateClass)
 {
    FileRaii fileGuard("test_ntuple_evolution_added_intermediate_class.root");
 
+   EXPECT_NO_STREAMER_OR_DICTIONARY();
+
    ExecInFork([&] {
       // The child process writes the file and exits, but the file must be preserved to be read by the parent.
       fileGuard.PreserveFile();
@@ -639,12 +621,6 @@ struct AddedIntermediateDerived : public AddedIntermediateBase {
       auto model = RNTupleModel::Create();
       model->AddField(RFieldBase::Create("f", "AddedIntermediateDerived").Unwrap());
 
-      // TStreamerInfo::Build will report a warning for interpreted classes (but only for base classes).
-      // See also https://github.com/root-project/root/issues/9371
-      ROOT::TestSupport::CheckDiagsRAII diagRAII;
-      diagRAII.optionalDiag(kWarning, "TStreamerInfo::Build", "has no streamer or dictionary",
-                            /*matchFullMessage=*/false);
-
       auto writer = RNTupleWriter::Recreate(std::move(model), "ntpl", fileGuard.GetPath());
       writer->Fill();
    });
@@ -674,6 +650,8 @@ TEST(RNTupleEvolution, RemovedBaseClass)
 {
    FileRaii fileGuard("test_ntuple_evolution_removed_base_class.root");
 
+   EXPECT_NO_STREAMER_OR_DICTIONARY();
+
    ExecInFork([&] {
       // The child process writes the file and exits, but the file must be preserved to be read by the parent.
       fileGuard.PreserveFile();
@@ -693,12 +671,6 @@ struct RemovedBaseDerived : public RemovedBaseIntermediate {
       auto model = RNTupleModel::Create();
       model->AddField(RFieldBase::Create("f", "RemovedBaseDerived").Unwrap());
 
-      // TStreamerInfo::Build will report a warning for interpreted classes (but only for base classes).
-      // See also https://github.com/root-project/root/issues/9371
-      ROOT::TestSupport::CheckDiagsRAII diagRAII;
-      diagRAII.optionalDiag(kWarning, "TStreamerInfo::Build", "has no streamer or dictionary",
-                            /*matchFullMessage=*/false);
-
       auto writer = RNTupleWriter::Recreate(std::move(model), "ntpl", fileGuard.GetPath());
       writer->Fill();
 
@@ -738,6 +710,8 @@ TEST(RNTupleEvolution, RemovedIntermediateClass)
 {
    FileRaii fileGuard("test_ntuple_evolution_removed_intermediate_class.root");
 
+   EXPECT_NO_STREAMER_OR_DICTIONARY();
+
    ExecInFork([&] {
       // The child process writes the file and exits, but the file must be preserved to be read by the parent.
       fileGuard.PreserveFile();
@@ -757,12 +731,6 @@ struct RemovedIntermediateDerived : public RemovedIntermediate {
       auto model = RNTupleModel::Create();
       model->AddField(RFieldBase::Create("f", "RemovedIntermediateDerived").Unwrap());
 
-      // TStreamerInfo::Build will report a warning for interpreted classes (but only for base classes).
-      // See also https://github.com/root-project/root/issues/9371
-      ROOT::TestSupport::CheckDiagsRAII diagRAII;
-      diagRAII.optionalDiag(kWarning, "TStreamerInfo::Build", "has no streamer or dictionary",
-                            /*matchFullMessage=*/false);
-
       auto writer = RNTupleWriter::Recreate(std::move(model), "ntpl", fileGuard.GetPath());
       writer->Fill();
    });
@@ -789,6 +757,8 @@ TEST(RNTupleEvolution, RemovedSecondBaseClass)
 {
    FileRaii fileGuard("test_ntuple_evolution_removed_second_base_class.root");
 
+   EXPECT_NO_STREAMER_OR_DICTIONARY();
+
    ExecInFork([&] {
       // The child process writes the file and exits, but the file must be preserved to be read by the parent.
       fileGuard.PreserveFile();
@@ -808,12 +778,6 @@ struct RemovedSecondBaseDerived : public RemovedSecondBaseFirst, public RemovedS
       auto model = RNTupleModel::Create();
       model->AddField(RFieldBase::Create("f", "RemovedSecondBaseDerived").Unwrap());
 
-      // TStreamerInfo::Build will report a warning for interpreted classes (but only for base classes).
-      // See also https://github.com/root-project/root/issues/9371
-      ROOT::TestSupport::CheckDiagsRAII diagRAII;
-      diagRAII.optionalDiag(kWarning, "TStreamerInfo::Build", "has no streamer or dictionary",
-                            /*matchFullMessage=*/false);
-
       auto writer = RNTupleWriter::Recreate(std::move(model), "ntpl", fileGuard.GetPath());
       writer->Fill();
    });
@@ -841,6 +805,8 @@ TEST(RNTupleEvolution, RenamedBaseClass)
    // RNTuple currently does not support automatic schema evolution when a class is renamed.
    FileRaii fileGuard("test_ntuple_evolution_renamed_base_class.root");
 
+   EXPECT_NO_STREAMER_OR_DICTIONARY();
+
    ExecInFork([&] {
       // The child process writes the file and exits, but the file must be preserved to be read by the parent.
       fileGuard.PreserveFile();
@@ -857,12 +823,6 @@ struct RenamedBaseDerived : public RenamedBase1 {
       auto model = RNTupleModel::Create();
       model->AddField(RFieldBase::Create("f", "RenamedBaseDerived").Unwrap());
 
-      // TStreamerInfo::Build will report a warning for interpreted classes (but only for base classes).
-      // See also https://github.com/root-project/root/issues/9371
-      ROOT::TestSupport::CheckDiagsRAII diagRAII;
-      diagRAII.optionalDiag(kWarning, "TStreamerInfo::Build", "has no streamer or dictionary",
-                            /*matchFullMessage=*/false);
-
       auto writer = RNTupleWriter::Recreate(std::move(model), "ntpl", fileGuard.GetPath());
       writer->Fill();
    });
@@ -890,6 +850,8 @@ TEST(RNTupleEvolution, RenamedIntermediateClass)
    // RNTuple currently does not support automatic schema evolution when a class is renamed.
    FileRaii fileGuard("test_ntuple_evolution_renamed_intermediate_class.root");
 
+   EXPECT_NO_STREAMER_OR_DICTIONARY();
+
    ExecInFork([&] {
       // The child process writes the file and exits, but the file must be preserved to be read by the parent.
       fileGuard.PreserveFile();
@@ -909,12 +871,6 @@ struct RenamedIntermediateDerived : public RenamedIntermediate1 {
       auto model = RNTupleModel::Create();
       model->AddField(RFieldBase::Create("f", "RenamedIntermediateDerived").Unwrap());
 
-      // TStreamerInfo::Build will report a warning for interpreted classes (but only for base classes).
-      // See also https://github.com/root-project/root/issues/9371
-      ROOT::TestSupport::CheckDiagsRAII diagRAII;
-      diagRAII.optionalDiag(kWarning, "TStreamerInfo::Build", "has no streamer or dictionary",
-                            /*matchFullMessage=*/false);
-
       auto writer = RNTupleWriter::Recreate(std::move(model), "ntpl", fileGuard.GetPath());
       writer->Fill();
    });
diff --git a/tree/ntuple/test/ntuple_pages.cxx b/tree/ntuple/test/ntuple_pages.cxx
index 2cfea078846b7..909f091072887 100644
--- a/tree/ntuple/test/ntuple_pages.cxx
+++ b/tree/ntuple/test/ntuple_pages.cxx
@@ -13,7 +13,6 @@ class RPageSourceMock : public RPageSource {
    std::unique_ptr<RPageSource> CloneImpl() const final { return nullptr; }
    void LoadPageListImpl(const ROOT::RNTupleLocator &, unsigned char *) final {}
    void LoadSealedPageImpl(const ROOT::RNTupleLocator &, RSealedPage &) final {}
-   void LoadStreamerInfo() final {}
    std::unique_ptr<ROOT::Internal::RPageSource>
    OpenWithDifferentAnchor(const ROOT::Internal::RNTupleLink &, const ROOT::RNTupleReadOptions &) final
    {
diff --git a/tree/ntuple/test/ntuple_test.hxx b/tree/ntuple/test/ntuple_test.hxx
index 32ea44985503e..1a12aa84bdd0a 100644
--- a/tree/ntuple/test/ntuple_test.hxx
+++ b/tree/ntuple/test/ntuple_test.hxx
@@ -150,4 +150,11 @@ void PatchRNTupleSection(std::string_view filePath, std::uint64_t sectionSeek, s
                          std::uint64_t patchedOffsetIntoSection, const std::byte *bytesToWrite,
                          std::size_t bytesToWriteLen, EEndianness sectionEndianness);
 
+// TStreamerInfo::Build will report a warning for interpreted classes (but only for members).
+// See also https://github.com/root-project/root/issues/9371
+#define EXPECT_NO_STREAMER_OR_DICTIONARY()                                                                          \
+   ROOT::TestSupport::CheckDiagsRAII diagNoStreamerOrDictRAII;                                                      \
+   diagNoStreamerOrDictRAII.optionalDiag(kWarning, "TStreamerInfo::Build", "has no streamer or dictionary", false); \
+   diagNoStreamerOrDictRAII.optionalDiag(kWarning, "TClass::Init", "no dictionary for class", false)
+
 #endif